garden

Automation is a lofty goal in many industries, but not always straightforward to execute. Welding car bodies in the controlled environment of a production line is relatively straightforward. Maintaining plants in a greenhouse, however, brings certain complexities due to the unpredictable organic processes at play. Hexagrow is a robot that aims to study automation in this area, developed as the final year project of [Mithira Udugama] and team.

The robot’s chassis is a very modern build, consisting of carbon fiber panels and 3D printed components. This kind of strength is perhaps overkill for the application, but it makes for a very light and rigid robot when the materials are used correctly.

Testing soil pH isn’t easy, but Hexagrow is up to the challenge.

It’s the sensor package where this build really shines, however. There’s the usual accoutrement of temperature and humidity sensors, and a soil moisture probe, as we’d expect. But there’s more, including an impressive soil pH tester. This involves a robotic arm with a scoop to collect soil samples, which are then weighed by a load cell. This is then used to determine the correct amount of water to add to the sample. The mixture is then agitated, before being tested by the probe to determine the pH level. It recalls memories of the science packages on Mars rovers, and it’s great to see this level of sophistication in a university project build. There’s even a LIDAR mounted on top for navigation purposes, though it’s not clear as to whether this sensor is actually functionally used at this point in development.

There’s nothing quite like having a garden in your backyard. You get tomatoes with flavor. Fresh herbs are easy. If you’d like to go crazy, you can always grow a gigantic pumpkin. But there’s a problem with gardening: the work. You’ve got to water, and you’ve got to weed. You’ve also got to deal with the thousand ladybugs you bought for a laugh.

For his Hackaday Prize entry, [Kent] has solved at least one of these problems. It’s an Internet of Things rain barrel. It’s designed to be as simple as possible so that anyone can set it up in just a few hours, and there’s also an option to make this rain barrel solar powered, making it eminently sustainable.

The design of this rain barrel begins as you would expect, with a 55-gallon rain barrel collecting water from [Kent]’s gutters. At the bottom of this barrel is a bunghole, and from that, a 12-volt pump sucks up the water and dispenses it into the garden bed. Everything is controlled through a Particle Photon, one of the easiest ways to set up an Internet of Things project, and yes, you can control this entire setup with an Alexa. The future is now.

Below, you can check out a few of the demo videos [Kent] put together for his project. One of them is solenoids clicking off to Deep Purple’s Smoke on the Water because if you’re going to build an Internet of Things thing with clicky electromechanical valves, you might as well make it play music.

Hackaday.io user [Prof. Fartsparkle] aims to impress us again with MoAgriS, a stripped-down rig for bringing crops indoors and providing them with all they need.

This project is an evolution of their submission to last year’s Hackaday Prize, MoRaLiS — a modular lighting system on rails — integrating modules for light, water, airflow, fertilizer and their appropriate sensors. With an emphasis on low-cost, a trio of metal bars serve as the structure, power and data transmission medium with SAM D11 chips shepherding each plant.

Reinforced, angled PCBs extend rails horizontally allowing the modules to be mounted at separate heights. Light module? Up top. Water sensor? Low on the rails above the pot’s rim. You get the idea. 3D printed clamps attach the rails to the plant’s pot with a touch of paint to keep it from sticking out like a sore thumb among the leaves.

Airflow modules replicate wind currents — the lack of which results in thin, fragile stems — and light modules include a soft white LED to accompany and mitigate the full-spectrum LEDs’ pink neon-like glow. To manage watering the plants, [Prof. Fartsparkle] initially wanted to use one pump to distribute water to every plant, but found some smaller pumps at a low enough price-point to make one per plant viable — and simpler to integrate as a module as well!

Gardening is a rewarding endeavour, and easily automated for the maker with a green thumb. With simplicity at its focus, Hackaday.io user [MEGA DAS] has whipped up a automated planter to provide the things plants crave: water, air, and light.

[MEGA DAS] is using a TE215 moisture sensor to keep an eye on how thirsty the plant may be, a DHT11 temperature and humidity sensor to check the airflow around the plant, and a BH1750FVI light sensor for its obvious purpose. To deliver on these needs, a 12V DC water pump and a small reservoir will keep things right as rain, a pair of 12V DC fans mimic a gentle breeze, and a row of white LEDs supplement natural light when required.

The custom board is an Arduino Nano platform, with an ESP01 to enable WiFi capacity and a Bluetooth module to monitor the plant’s status while at home or away. Voltage regulators, MOSFETs, resistors, capacitors, fuses — can’t be too careful — screw header connectors, and a few other assorted parts round out the circuit. The planter is made of laser cut pieces with plenty of space to mount the various components and hide away the rest. You can check out [MEGA DAS]’ tutorial video after the break!

If you compulsively search online for inexpensive microcontroller add-ons, you will see soil moisture measurement kits. [aka] built a greenhouse with a host of hacked hardware including lights and automatic watering. What caught our attention among all these was Step 5 in their instructions where [aka] explains why the cheap soil sensing probes aren’t worth their weight in potting soil. Even worse, they may leave vacationers with a mistaken sense of security over their unattended plants.

The sensing stakes, which come with a small amplifier, work splendidly out of the box, but if you recall, passing current through electrodes via moisture is the recipe for electrolysis and that has a pretty profound effect on metal. [Aka] shows us the effects of electrolysis on these probes and mentions that damaged probes will cease to give useful information which could lead to overworked pumps and flooded helpless plants.

There is an easy solution. Graphite probes are inexpensive to make yourself. Simply harvest them from pencils or buy woodless pencils from the art store. Add some wires and hold them with shrink tube, and you have probes which won’t fail you or your plants.

[Asa Wilson] and his wife picked up a 10’x12′ greenhouse from Harbor Freight that for their location required some serious changes, understandable since they’re in Colorado on the western slope of Pike’s Peak where the winds are strong and the normal growing season is short. After assembling it on a concrete footing and adding some steel bracing, they got to work on adding an environment management system based around a Raspberry Pi. Read on for a look at the modifications they made.

Composting serves an important purpose in our society, reusing our food scraps and yard waste to fertilize gardens rather than fill up landfills. Knowing that most people don’t compost, [Darian Johnson] set out to create a Arduino-controlled composting system to make it as simple as possible. It monitors your bin’s moisture, temperature, and gas emissions to ensure it’s properly watered and aerated.

[Darian]’s project combines a MQ4 gas sensor that detects combustible gas, a soil moisture sensor, and a temperature and humidity probe. The nearby water reservoir is monitored by an ultrasonic sensor that keeps track of the water level; a pump triggered by a TIP120 turns on the water. Meanwhile, a servo-controlled vent keeps the air flowing just right.

The Smart Composting System sounds like it would be useful to home gardeners; it’s a Best Product finalist in the 2017 Hackaday Prize.